Here, we are continuously waiting for visibility of elements having className as "dummy" that doesn't exists means Appium is getting continuous commands till timeout provided in explicit wait. And after waiting for timeout "timeInSec", it will throw timedout exeception that we are catching in catch block.
So call "wait(int timeInSec)" method wherever you want to wait, Appium will not get timedout.

2. Second solution would be to increase "New_Command_Timeout" for Appium. That we can achieve by setting it in DesiredCapability like below: